Treating HIV Helps Prevent New Infection

ï»¿SEATTLE -- More HIV treatment in a community results in fewer new HIV infections, a South African study has revealed.

by Ed Susman Contributing Writer, MedPage Today

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This study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

This prospective observational study in South Africa found that increasing antiretroviral coverage in a rural area where HIV is endemic led to a significant decrease in new HIV infections.

Note that antiretroviral treatment was initiated between 2004 and 2008 in about 20,000 HIV-infected individuals in 17 communities.

SEATTLE -- More HIV treatment in a community results in fewer new HIV infections, a South African study has revealed.

When HIV treatment coverage reached 20% of the infected population, a surveillance project indicated a 22% decline in HIV infections community-wide (P=0.002), said Frank Tanser, PhD, associate professor of health and population studies, University of KwaZulu-Natal, Richards Bay, South Africa.

"In communities where HIV treatment achieved 30%, the individuals' HIV acquisition was 38% less likely (P<0.001)," Tanser said in a press briefing here at the Conference on Retroviruses and Opportunistic Infections.

"These results clearly demonstrate that the rate of new HIV infections can be reduced and that this can be done in a typical sub-Saharan African setting," he said. "This is the first empirical evidence to date that treatment can be prevention."

Tanser and colleagues put together two databases involving treatment in an area of South Africa with high rates of HIV prevalence. When they analyzed the results, they were able to observe "a robust decline in transmission as the coverage of HIV treatment was rolled out."

In the KwaZulu area studied, HIV prevalence is 24% in an area with high levels of unemployment and poverty. The Hlabisa HIV Treatment and Care Programme, funded through the American-based President's Emergency Plan for AIDS Relief (PEPFAR), delivers HIV and AIDS treatment programs in 17 communities. Since 2004 and 2008, Tanser said, some 20,000 individuals were initiated on treatment among 228,000 people in the communities studied.

The data and treatment was married to population-based HIV surveillance since 2003, which studies HIV acquisition in the area. About 75% of the population found to be HIV negative retest each year, allowing epidemiologists to determine infection rates. In the study, the researchers followed 16,667 HIV-negative repeat-testers, Tanser said. All participants in the analysis had to have participated in the project at least twice and had to be 15 years of age or older.

Strengths of the observational study include the direct measurement of HIV acquisition in a longitudinal prospective cohort of all adults in an entire population, as well as directly measured antiretrovirus status in every infected individual, he noted. In addition, the researchers controlled for a wide range of key determinants of HIV acquisition.

"Randomized controlled treatment-as-prevention trials are the next step," Tanser said. "Our findings suggest that attaining high levels of antiretroviral coverage through existing, decentralized, public-sector antiretroviral programs is an effective means of reducing the rate of new HIV infections in hyper-endemic rural settings in sub-Saharan Africa."

James Hakim, MD, chairman of the department of medicine at the University of Zimbabwe College of Health Sciences in Harare, said the findings demonstrate that "rolling out antiretroviral therapy appears to be having an impact in reducing incidence of HIV in the community beyond just reducing the morbidity and mortality among the individuals receiving treatment." Hakim was not involved in the study, but moderated the press briefing where Tanser reported his findings.

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